Specific foods which contain particular nutrients may increase sperm/semen production that should lead to a more satisfying sexual experience:
Foods containing Vitamin B-12, C or E, Zinc: citrus fruits (oranges, grapefruit, lemon), broccoli, meat, oysters, eggs, nuts and seeds.
Selenium: Tuna, meat, eggs and cheese.
Folic Acid: Greens, beans and citrus fruits.
Basically, a well-balanced diet and healthy lifestyle should keep your semen/sperm production high!