When two men have a wedding, do they both wear suits, or does one wear a dress?

They usually wear suits, but sometimes they wear kind of "celebratory" but somewhat masculine-constructed clothes.  

I’ve only been to one gay wedding and both men wore suits.

We weren't told what we could or couldn't wear, but we wanted a traditional wedding that represented our cultures so we both wore three piece suits with different color waistcoats and opposite color boutonnieres. It was magical. 

Both wear suits.  It's some different from lesbians who OFTEN DO wear one sort of garment.

Anyone, whatever gender, can wear whatever they choose at their wedding.  In a hetero wedding, the bride doesn't have to wear a dress and the groom doesn't have to wear a suit.  

At one I heard of a while back, they both wore fancy dress - like cosplay - and all the guests did as well. I think it was a 'Star Wars' themed wedding.A male couple can wear suits or casual clothing - just what they normally wear or whatever they choose to wear.  Being gay doesn't mean that they cross-dress.  Most cross-dressers are straight.When two women marry they can both wear dresses, both wear suits or each wear whatever they feel happiest in.

Typically both wear suits.  It would be somewhat rare for one of them to wear a wedding dress.

Probably both suits. 

Whatever they want. My brother and his husband both wore suits.

They wear suits most of the time.

But sometimes one partner will mimic a woman.

They wear whatever they like just as any couple getting married does.