There is this marriage --
Samuel Lewis/Emily Alice Jeynes 2nd qtr 1890 Birmingham 6d 223
There is also another one in 1894 but idealy you need the birth cert for Mary so that you can find out her mothers name. I suggest you send for one or both of the cert's you have details for and specify you want the one with Samuel named as the father.
As for Mr Mullins, you only say he was "round the corner", do you know what area or roads involved, if so, have you looked at Electoral Rolls or in the Directories for that time period
bren