My fwb (28f) and I (32m) regularly set up a gloryhole at my place for she and I to have fun with (I am orally bi).

A few weeks ago on our post for the gloryhole, I was checking the responses and one of them was from her brother (he had included a face pic in his reply). His cock and body were exquisite, so I deleted his face pics and showed my fwb who said yes to his pics. Probably not my proudest moment, but we're rarely 100% in agreement on guys.

I set up a time for him to stop by the gloryhole and we had a blast sucking him off. He was probably between 8 and 9 inches and decently thick with a huge mushroom head. My fwb was getting so wet and into it while I was rubbing her pussy that she suddenly got up, turned around, and jammed her brother's whole cock in her pussy before I even knew what was happening. The sounds of them moaning together was hot af as he was slamming his cock balls deep into his sister's pussy. After about 10 minutes, he couldn't last anymore and my fwb's knees went week as her brother shot his load deep inside her. When he pulled out, she and I spent a few minutes cleaning him up orally before he left without a word.

Cut to a few days ago, she missed her period and the at home test came back positive. She's got it figured out, but it makes me wonder if it's her brother's, mine, or maybe someone else. To clarify, she rarely doesn't use protection so that whole scenario was not the norm for her.

Now, she's still talking about her gloryhole fuck and how she wants us to meet with him again, maybe even face to face. I don't think I should tell her, but I'm not 100% sure. She just keeps bugging me about it and I'm running out of excuses.