Not currently. You're only supposed to have one account.
I know bughouse simuls are a part of bughouse culture, but it's not currently supported. Using two accounts, in addition to being a violation against multiaccounting rules, creates concerns about rating manipulation - some people sandbag with one account and then self-partner to inflate their main account's rating.
The proper way to handle it would be to display both boards side-by-side and have a single account controlling both boards. That's obviously not implemented yet, but if you use the "Make a suggestion" feature under the Help menu, that will help let staff know what people want and what the community considers important.
Just a quick question, are we allowed to create a 2nd account and partner on two different boards? I have seen a lot of people do it, and I want to know if it's legal or not.