Does anyone else experience the feeling of someone or something lie behind them in bed.?

My girlfriend and I hove both experienced this unexpected phenomena on several occasions both together and alone in bed.Also the feeling of something jump on the bottom of the bed and slowly work it way up to our faces ; sometimes I feel blowing on my face very gently and often my face is stroked ,It never hurts or trys to scare me although sometimes it is a little alarming.It can feel as its under the quilt between your legs but again never aggressivley and I never feel it go only arrive.It sounds terrible but its realy not that scary tome now but Im curious to find out what it could be