Welcome to Gaia! ::

I don't know if it would work for a long-term relationship, but it's DEFINATLEY something I like to watch see. xd Think Tsume and Kiba from Wolf's Rain, or possibly L and Light from Death Note (though one or the other is usually portrayed as uke). I'd list a few pairs from actual yaoi/ shonen-ai anime, but my brain is dead at the moment...

Anyway, the appeal in seme/seme lies in the power struggle (at least to me it does). I've seen similar topics on a few of my BDSM guilds, asking for the opinions of members if two dominant people can make a go of a relationship. It doesn't seem to be as popular as uke/uke, but quite a few people seem to support the possibility, myself included.

Let's sum this up (I'm in a hurry)-

uke/uke relationships are sweet and usually long-lasting relationships, or at least that's been the case in the uke/uke relationships I've seen operating in real life and heard about online. ask any reputable member of a BDSM community- most people have some tendency to switch sexually, so in an uke/uke relationship you may have one uke who is slightly more seme on occasion, or maybe both of them can trade off. There are almost no relationships where one person is always dominant and one is always submissive. in fact, uke/uke works better in this case, because dominants tend to get resentful of being controlled if they don't have enough of a switch tendency (or if their partner doesn't). seme/seme is incredibly fun to watch ( I LOVE seeing tough guys brought to their knees- the more literally the better), but for an actual relationship, the uke/uke pairing would have a better chance.