max headroom garment
Refers to any upper-body article of clothing (i.e., blouse, t-shirt, nightgown, etc.) that has sufficient "excess looseness" in front of the wearer to allow someone's else's head to be tucked up in underneath so that said person can snuggle his/her head against the wearer's bare chest without the garment's having to be removed.
Snuggly guy: I love how Tiffany wears such a loose PJ top to bed; it's a really awesome "max headroom garment", in that I can easily slip my head underneath the hem and nuzzle up to her boobs while we sleep, even when it's too chilly in the bedroom for her to sleep "topless".