One easy way is to make a copy of the tree and make yourself the new "author."
Click on [Download / export this family]
Select the Family Script format option and click [Download].
Your download will be an exe or zip file which you should open to extract the FamilyScript file. It will be a txt file.
Back in the Family Echo screen, click on [My Account].
Click on [Create or import new family].
Then click on Import GEDCOM or FamilyScript...].
Click on [Browse] and locate the txt FamilyScript file you extracted.
Click on [Import].
There will now be a drop down menu that will allow you to pick yourself as the new "yourself" person.
Lastly click on [Finish import].
Tell your boyfriend the old tree is his to do with as he pleases and the new one is yours. 
