The idea here isn’t to present a complete Gay Kama Sutra! That would be a challenge indeed
One of the best things about sitting sex is that it gives the man who receives his partner’s penis the 
opportunity to experience the other side of sex – controlling it, controlling the pace and depth of thrusting, and setting the rhythm and speed with which the couple move towards orgasm.
If a man usually takes the role of the bottom, then sitting on top and riding his partner’s cock may be a strange experience for him. He needs to be confident in the assumption that if he controls the pace of sex, the man on the bottom will be having a good time as well! If the man on top begins to feel tired, or decides he’s worked hard enough in that sex position, it’s easy enough to roll over onto your sides and continue sex without withdrawing his partner’s penis.
And as in all sex, it’s important that the man on top, riding his partner’s penis, does it primarily to pleasure himself. Sex isn’t just about pleasuring your partner: you need to be assertive enough to take pleasure in a selfish way from time to time, safe in the assumption that when you are turned on, your partner will find sex more arousing and will enjoy himself even more.
During missionary position sex, the bottom can help his partner get into him by raising his own knees and legs, holding his knees close to his chest, allowing his partner full access to his buttocks and anus: during sex, he can move his legs and knees into a variety of positions, and raise or lower his hips to give his partner variations in the depth of penetration; his partner, by contrast, can vary the speed and depth to which he thrusts, so as to tease and tantalise the bottom.
