I think you're right, Max, with both the reasons for more bubbles after sex and not being able to piss straight. I have more immediately after I've ejaculated and I suppose this is the reason I first thought of precum causing the covering of the fluids with bubbles any time I'm horny. Any widening of the dick slit probably keeps the stream from being one good straight line and during sex, especially with lots of pounding, the slit is likely to become "stretched" out of its normal shape.

This thread has included this additional aspect and has made me think of even more urological characteristics!
Thanks.

Luke