And NOT because I'm a bad singer.
And not because I rarely play my guitar, but because everytime I try to sing around him I either get all goofy and giggly or I sing badly on purpose and I can't stop myself!
I jut can't do it!
I mean, I'm not a great singer, but I'm not awful! And I can sing indie pretty well.
Just not in front of him! UGH!

Try to block things from your mind if you can and concentrate on the song.
That's what my sister in law does in her band. Her boyfriend is the drummer and he also does lead guitar sometimes and she's the lead singer. That's what she tells me she does.

Let the music drive you. If you can feel it, you can sing it. I play in several bands with my friends and that always helps me.

I can feel it just fine! I don't know what it is! I just can't! I've tried and I can't! lol

is it just because you're goofy around them? -b/c i have the same problem w/ my friends and w/ Kareoke at their houses...i just dont take it seriously, and im constantly laughing ....idk why, i just can't be "straight-laced" around them
...which then later i get made fun by them

I totally understand you! It is VERY hard....try signing harmony behind a perfectionist!! I sing with my husband and although he adored my singing while we were dating he is very critical about it now that we are married. HE is the HARDEST person to sing harmony with (because his melody is inconsistant and his keys are very hard to pluck a harmony out of) but when we get it together it is beautiful! When we first started singing together I was "goofy" but you just have to block out the nerves (which is what caused my goofiness) and focus on the music. Get lost in it and everything will work out!

Hope you bust the "giggles" Good luck!