I've been in relationships with people 10 years older than me before, and in the gay community it's not actually all that uncommon for older men to be interested in younger ones. I could see it, though I wouldn't like the vibe if Jeeves were too much older than Bertie. Of course, the older you get, the less those few extra years would matter -- 17 and 27 seems a huge gap, where 37 and 47 isn't all that much, really. I do tend to go for them being no more than about 7-8 years apart, though, and preferably really only about 5.