We have finally managed to get a babysitter for DS (4) who is reliable and who DS loves and is happy to be left with. Both dh and I are happy with her and wouldn't like to lose her. However she has just texted dh to ask if its alright if her OH comes with her when she sits for us. Dh and I have discussed it and although we have no real reason to object (aside from we have not met him) neither of us are comfortable with it and so are going to say "No". Are we being unreasonable?