A little friendly heckling is par for the course when it comes to best man and and groom’s speeches (and others, depending where you’re from.)
The most important thing to remember is the spirit of the heckle. This is a wedding, not a late show at the Comedy Store. These heckles aren’t meant to be cruel; they’re coming from friends and loved ones, not strangers. They may be friends and loved ones with limited comedic ability, but generally their heart is in the right place, so don’t take it too personally.
DON’T BE AN EASY TARGET
Some phrases are begging for a heckle. If you’re expecting every ‘thank you’ in your speech to get a heckling “you’re welcome” in response, try not to use those exact words too often. “I’m grateful to…” is a good substitute.
Also, and this may seem obvious, put some preparation into your speech. With a well-prepared speech (as opposed to a hesitant, fumbling one,) it’s less likely you’ll hear “He needs some help!”
HAVE A FEW COMEBACKS READY
Have a few in the back of your mind, and do your best to keep your comebacks gentle. Even if the heckler’s a jerk, if you go overboard, throw a low blow or get too personal in your response, you’ll lose the moral high ground and end up being the bad guy.
Some examples of comebacks:
“You just bought your own dinner.” (If you’re the groom or father of the bride.)
“You missed rehearsal. We cut your part out.”
“Sorry about that. He’s still adjusting to parole.”
"This is why you’re single.”
“It’s not his fault. He hasn’t been the same since the syphilis diagnosis.”
All that said, remember that you’re in control, and this is your moment. So while some heckling may be the tradition where you are, you don’t want to let it overwhelm your speech.
You don’t want the guests who aren’t heckling to get bored and stop paying attention because they feel as if you’re only talking to you friends. (Trust me, this happens.) A good-natured exchange or two is fun. But too many and it knocks the speech off balance.
In stand-up comedy, the general rule for hecklers is to strike back only when absolutely necessary — which is when you’re absolutely certain the rest of the audience has heard the comment. Once you’ve hit back, go right back to your material, and if it’s strong enough, the hecklers will quiet down because they’re enjoying the show, and/or they’ve realized their time has passed.
And, as I said to a groom’s speech client who was worried his drunk buddies would keep heckling him to kiss his wife, go for it! (Assuming it’s ok with her, of course.) Hit them with, “Happy to! Look at her!” The more you fight what they’re asking for, the more they’ll push.