It all depends on your libido and whether your partner is also in that frame of mind and she freely consents and enjoy every moment of experience she and you encounter. There should not be any boredom(same old boring sex position or seduction) so you find ways to spice your sexual relationship with your partner. Eating foods that create high libido would help you withstand the prolong sexual relationship. See that you can withstand it's experience and it does not effect your kidneys.
Seduce your partner into having sex by role playing and engaging in adult games, teasing and flirting with her so she feels she in that right of frame of mind. Ultimately what is important is that there must be mutual satisfaction and pleasure derived from this encounter and not a drudgery or ordeal to either one of the partners. Sexual encounters should enhance your relationship and not otherwise.