As it's his birthday you should think about what will please him and make him happy. Is he a sentimental, romantic guy who would be really touched that you ent to the effort, or is he more of a lad who would prefer a six pack of beer?
Hell no! The first year I was with my boyfriend (now husband) I did a "bloke" cake. I bought a chocolate sponge base and iced it with the words "ARSE" in beautiful blue icing and surrounded with a ring of smarties. He nearly wet his pants laughing and still tells his friends about it 5 years on!
On another note, there is much truth to the saying "a way to a man's heart is through his stomach" Wise words!
As Nell says, it kind of depends on the guy - but if you're having a party, then definitely go ahead and get baking, because everyone else will love it, even if he doesn't... Besides, wouldn't he have to be a strange and mean individual not to be touched that you'd gone to such an effort to make him feel special and to mark an important birthday?
I made my husband a two-tier pork pie instead of a birthday cake a couple of years back. Men are often savoury rather than sweet critters and are easily amused by things out of scale. Check out Pimp That Snack.com for great ideas.
And why not just ASK him if he'd like a cake?
I think it's a lovely, generous idea. It proves that you care about him and are trying to make his day special. Besides, I've never known a man turn down cake!
as nell says; what is your guy llike? if you think he'll like it go for it. make it funny and he'll think its cute or oput a photo of him on or something. whatever you think he'll lke do it!