In M2K2's IRC channel, we once came up with discussing how to sequence break fucking.
The exact quote was: "still fuck though even if you're not trying to sequence break", when someone talked about Metroid Fusion. He meant to say "fun", but the damage was already done and it was no stopping it.
However, I think skipping foreplay was the only trick anyone came up with...
Preparation is the key. Just keep your semen in a bottle, so you can quickly dispatch it wherever appropriate in case something like "sex" starts to occur in your life.
However, going for speed in sexual intercourse is generally disliked by women. I strongly advise against speedrunning, let alone sequence breaking. It can seriously decrease your replay value.