i once saw an awesome pic of Betty Ross sitting on top of Bruce Banner wanting to get some ...well.....action, and nearly snoring. She starts insulting Bruce and he turns into Hulk. She's quite happy afterwards
Hulk is...endowed enough, that he's spent time as a sex slave recently, in Defenders miniseries. Be that as it may, unless it's Professor Hulk there's no chance of the magic lasting, as Lois will pine again for Clark Pureheart.
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"I'm not smart so much as I am not dumb." - Harlan Ellison
Think of it this way ......most forms of the Hulk are basically rage-imbued maniacs that just try to smash everything they come across. If an obstacle or issue arises then the solution is to hit it as hard and as fast as possible.
That is the Hulk way .....smash!
When it comes to ....erm .....'relations' ......the Hulk (at least almost all forms of the Hulk) would just do the old 'Hulk smash' thing, in this case a slam,bang,thankyou maam (although I doubt the Hulk would even say thank you).
The Hulk would not only be a horrible lover but he would probably tear apart whatever poor soul he was with.
Conclusion: The Hulk (at least most versions of the Hulk) would probably be one of the worst lovers in comicdom(with the probably exception of the Thing). His whole thing would be 'smash,' and thus only enjoyable to one person ....the Hulk.
Superman on the other hand is said to be constantly holding back his strength in fear of hurting people. This indicates a very large degree of self-control.
Self-control.
Thus he is able to put others first, something that can translate into the bedroom.
Thus no 'Hulk smash' when it comes to Superman.
And anyways, Kal El is FAR better looking than the Hulk.
That's why this has to be Professor Hulk or the Gray Hulk, both of whom had brains and charm, if rough-edged. Rick Jones' squeeze Marlo, her first appearence was as an arranged date with the Gray Hulk; she spends the night, and comes out next morning exhausted but satisfied beyond words.
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"I'm not smart so much as I am not dumb." - Harlan Ellison