if you two were in business together 50/50, then you would be responsible for 50% of the expenses. whether or not he paid for it personally or through the business makes no difference. theres still costs to owning that occur after its paid for, namely taxes, upkeep, maintenance, hydro etc.
if you want to get your portion of the profit, you also have to factor in your portion of the costs.
but regardless, asking here is the wrong place, this is a legal issue you need to discuss with a professional.
you can easily hire a lawyer for advice on an hourly basis.
and if I were in a business partnership, regardless who it is, i would expect my partner to contribute equally, or to the predetermined percentage. if that partner expects to profit from my business then they must contribute.
"In a ham and eggs breakfast, the hen is involved, but the pig is committed".
