It is well established that a lessor may not assert a forfeiture of a lease for failure to pay rent due under the lease where, with knowledge of the breach of the lease, he accepts rent from the lessee. Borst v. Ruff, 137 Conn. 359, 361-62, 77 A.2d 343 (1950). Nonpayment of rent does not, in itself, terminate a lease, but gives the lessor the option to terminate the lease by some unequivocal action clearly showing the exercise of that option, and a tender of rent after a breach of the covenant of payment, but before a declaration of forfeiture by some unequivocal act by the lessor, precludes the lessor from thereafter completing a forfeiture of the lease. Mayron’s Bake Shops, Inc. v. Arrow Stores, Inc., 149 Conn. 149, 156, 176 A.2d 574 (1961).