Quick question: 1.5

Understand L1, L2 and L3 but what is L1.5 in some of the reviews? Thanks in advance

If L1 uses the hand, L2 the mouth, and L3 the vag then surely L1.5 must involve feet. Don't quote me on this for it's just an educated guess.

I've used 1.5 in the past to indicate half-hearted BJ, or spit-wet hj.

Thanks for your input. Have seen it several times in reviews