if you are in the process of buying right now, do not try to buy. You can discuss it with the LO and have them run it by the UW, but it is an added complication. Also, you will take FICO hits for lender inquiries and for the new account, as well as possible loosing a few points when the lease drops off. SO it is not worth it if you are trying to get a mortgage right at this moment. Again, feel free to discuss it with your LO (make sure he has run it by the UW because many a person has been told something is OK by LO without UW consent and it has caused problems. The most important part is not taking any hits on DTI right now or on FICO.
