Haakaa question

Caitlin

When I put the haakaa on the side my LO is not nursing from, it rests on his legs parallel to the ground and the milk eventually fills up high enough to be touching my nipple. Is that unsanitary? I don't clean my nipple after he nurses before putting it on and feel like it must be similar to why you don't let a baby finish a bottle later once they've started to drink from it? Any feedback appreciated!