10 years' difference might not seem like a big deal...BUT it's not consistent and it depends on which stage of your life you're at: 10 years' difference at 20 can seem like more or less at other stages, so think long and hard about what you both want from your relationship in the long-term.
At 30, you're still young and beautiful, set for world domination and in your prime sexually, but what about 15 years later? According to statistics, the average relationship between a younger man and an older woman has a lifespan of 13 years.
People harp on and on about it, but you musn't forget the dreaded biological clock. If he's in no hurry to have kids and you're getting broody, it can cause problems for your relationship and worse: if you wait so long you have difficulty conceiving, you could miss out on having a family altogether.