I prank my friend's girlfriend in private, Wait!? My boyfriend will find out! Can we suddenly have NTR sex? (Seisho version)

My boyfriend's friend's hands are reaching for my boobs and crotch...I'm not allowed there because I'm going to hear a voice! ...I tried to run away because she told me it was definitely secret, but I got more excited than usual and seduced her friend, a beautiful girl who is an uncool guy, and took her to bed. Some of the GALs who are taken to bed have heart-pounding sex even though he is nearby...