What does my mates ex-girlfriend mean by this, help?

My mate still lives with his ex-girlfriend (well on the sofa) and have a kid together, this is what I want to know... last week I went around to his and was talking on the same sofa as him and his ex-girlfriend came in and sat on the one opposite us and I noticed her kept looking at me and didn't think to much of it then she got her mobile phone and like sat in a position which made her legs like "open" and she knew I looked and she kept looking at me and when I went out to play darts with my friend she looked at me and said bye, before this whilst being separated from my mate she has given me cuddles before, is she serious, flirting, winding me up or what?