Something that could work is a girl that is trying to seduce a guy by showing her holes or tits to him but some other guy just walks up to her and sticks his cock in her/between her tits?

I’m pretty sure I have (or will have) some scenes like that in my longer short stories. It’s a bit of a specific chain of events for a caption (finding a gif that involves an interruption like that). If you find a fitting gif for it, let me know :)