I just cut my boyfriends eyelashes..?

Not true. Think about how many eyelashes you've lost over the years. If they hadn't grown back you'd have no lashes. So even if cutting eyelashes stopped them from growing, the lashes would still fall out and replenish themselves. The truth about all the hair in the human body goes as follows. There can be upto three hairs in a single follicle all in different stages: one that is about to fall out, one that is firmly planted and another that is just starting to grow. Don't worry about it, but I bet he looks pretty silly in the meantime!