You get what you pay for. In my opinion, your boyfriend's father does not owe you for the mistakes he made. These tax returns are filed under your name, with information you supply, and you should review the returns and do your due diligence regarding taxes and penalties before signing and submitting your return.
The IRS requirements on estimated taxes are clear and readily available through a simple internet search. Penalties should show up on a line on your return, but when reviewing your return...
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