Lesbians by far. It's been acknowledged by women's gender studies academics. The idea comes from the fact that in patriarchal societies, masculinity is valued more than femininity. The idea of a woman liking women (masculine trait) is more acceptable than a man liking men (feminine trait). Both acts are viewed as wrong, because it steps outside of basic gender expectations. However, it's deemed as "more okay" for a woman to upgrade to masculinity than a man to downgrade to femininity. That's the generally accepted consensus among academics about the issue.

I don't know if "accepted" is the right word, coz I don't think either are accepted realistically. But I would say that lesbians are probably "more accepted", for the sole reason that girls can usually hug and even kiss in public and it'll just be a fun flirty girl thing, but if guys did that... we know what'd happen.