The premise is making a girl cheat. The girl is your friend's wife. Her husband's good friend decides he'd rather take advantage of the moment than worry about what it would do to his friendship.Him and her are close as well.

They'd gotten close by spending more and more time alone together, as her husband had been away often as of late.The idea is that while the two are playing a game, he turn it into a wager. As she loses round after round, the bets required of her become more and more interesting and much less civil. As uncomfortable as she becomes, she dug herself deeper and deeper into a hole

Perhaps soon he would be deep in that hole..

Kinks:
Huge cock / Intimidation Factor
- "It's so big!" and "I don't think it will fit", "It might hurt". Be creative.
I love the idea that she's intimidated by your size, still realistic though.
I'd suggest you're slightly bigger than her husband.
She's still able to comfortably (if even barely) able to fit you in her mouth and do a good job.
Yet, big enough that she's worried about letting you put it inside her, fearing that you'll stretch her.
It might hurt at first. She might even never be the same, but once it slips inside she makes that face.
Pure orgasmic pleasure~ Look up 'Ahegao'.

Distention > YES! Ruin her tight little pussy.
She hasn't been enjoyed for weeks. Her husband comes back tomorrow, but when he comes home,
she might not be able to feel him. She might also be too embarassed to let him near her,
her conscience knowing what she'd done.

Cheating, of course.
More Coercion rather than Seduction, Forced, as in pushed into doing something, but following through on her promises by choice; staying true to her word, having made the unfortunate wager.
The Blowjob? Is it sloppy? Well, it could be, though IRL she's generally pretty tidy. She keeps the saliva to a minium, keeping things lubricated, but in her mouth Not the cum tho... she hates the idea of letting her husband cum in her mouth.

So, make sure to make her promise to make you cum in her pretty little mouth!
Power Struggle; well, not really. He's just really strong, and she's quite small. It's easy for her to feel over powered and fragile next to this guy.
Lots of Cum. In her mouth and inside her.
Facials? Okay, just don't waste too much of it. Only enough to make her uncomfortable and mock her for letting you do it.
Like it rough? Maybe, but not too rough. Don't hurt the poor girl.
A slap that leaves a mark, or tying her wrists might get you somewhere.
Tickle her until she complies perhaps,
Stretch that tight little pussy if you consider that to be rough.
Maybe nibble on her tit.
Light Humiliation; Remind her from time to time that she is infact Cheating;
that her your friend would be so jeleous.
Ask if she'd done this for her husband before.
No Name Calling though, especially considering you're supposed to be a friend.

Titfucking? Titty fucking; well, you could, but she's kinda small, only a B-cup or C-32.
Perfect, round little tits and a body to dream about.

Clothed, or partially? CFNM? CMNF? Love that stuff. Makes it maybe a little more demeaning.
Braless and loses her shirt; wearing yoga pants?
A cute hoodie? I'm not overly into lingerie.
She generally just dresses too cute for her own good.

Pictures and Video: We could make this part of the story; a wager, betting so you'll delete them, only to get more out of her on the next bet, or push her limits for the opportunity to release her.

FFM? Was it her friend who pushed her into this? Why is it her who keeps having to let him cum inside her everytime? It was just supposed to be a quick blowjob.

Facefucking -sure. Take advantage of her almost any way you'd like,
as long as she'd agreed to make the bet.

Cum inside her. Yes. An absolute must. Creampie her several times. Make her do it to herself.
This would be the hardest thing for her. She'd know she could get pregnant. She'd even warn you that she's not on birth control, but you don't care. Still you'd make her follow through; make good on the silly wager she'd made.

Ideas for Steps:

1. She has to flash her cute little tits.
2. She loese her top.
3. She has to let you grope her.
4. Suck her nipples, making them hard.
5. Not wanting to do anything for real, she loses her panties.
6. Has to kiss you and turn you on.
7. Has to let you lick her pussy.
8. Gives you a blowjob and makes you cum in her mouth
9. Outercourse in your lap.
10. Has let you slip in; bareback.
11. She rides you.
12. Loses her mind and orgasms on your dick.
13. Has to keep going and can't stop until you finish inside her.