Of course you can. In particular lots of people have the desire for both, although in some cases they'd still prefer to focus on just one side at a time, while others would rather be mutually gaining. To make a ridiculously broad generalization, if you like power transfer associated with the gaining process, you probably want to focus on one side at a time, while if you just like fat and getting fatter then mutual gaining is more apt to what you want (but like all generalizations, there will be exceptions)
13 years