AMENDMENT ONE DATED MAY 1, 2021 TO INVESTMENT SUBADVISORY AGREEMENT for MML Total Return Bond Fund

Exhibit D(114)

AMENDMENT ONE

DATED MAY 1, 2021 TO

INVESTMENT SUBADVISORY AGREEMENT

for MML Total Return Bond Fund

WHEREAS, MML Investment Advisers, LLC ("MML Advisers") and Metropolitan West Asset Management, LLC (the "Subadviser") entered into an Investment Subadvisory Agreement (the "Agreement"), effective as of December 16, 2014, relating to the MML Total Return Bond Fund (the "Fund"); and

WHEREAS, MML Advisers and the Subadviser desire to amend the compensation of the Subadviser as described in the Agreement; and

WHEREAS, Section 15 of the Agreement permits the Agreement to be amended by a written instrument approved in writing by both parties;

NOW THEREFORE, IT IS AGREED THAT:

1. Capitalized terms used herein but not otherwise defined shall have the meanings given to those terms in the Agreement.

2. Section 4 – Compensation of the Subadviser is replaced in its entirety with the following:

The Subadviser will bear all expenses in connection with the performance of its services under this Subadvisory Agreement, which expenses shall not include brokerage fees or commissions in connection with the effectuation of securities transactions for the Portfolio. For the services provided and the expenses assumed pursuant to this Subadvisory Agreement, MML Advisers agrees to pay the Subadviser and the Subadviser agrees to accept as full compensation for the performance of all functions and duties on its part to be performed pursuant to the provisions hereof, a fee paid monthly, in arrears, at the following rate: [    ] If this Subadvisory Agreement becomes effective or terminates before the end of any month, the fee for the period from the effective date to the end of the month or from the beginning of such month to the date of termination, as the case may be, shall be prorated according to the proportion that such partial month bears to the full month in which such effectiveness or termination occurs.

3. Except as expressly amended hereby, all provisions of the Agreement remain in full force and effect and are unchanged in all other respects.

4. This Amendment may be executed in one or more counterparts, each of which shall be deemed to be an original and, all of which, when taken together, shall constitute one and the same instrument.

IN WITNESS WHEREOF, the parties hereto intending to be legally bound have caused this Amendment to be executed by their duly authorized officers or other representatives as of the day and year first above written.

MML INVESTMENT ADVISERS, LLC			METROPOLITAN WEST ASSET MANAGEMENT, LLC
By:	/s/ Xxxxxxx Xxxxxx		By:	/s/ Xxxxx Xxxxxxx
Name:	Xxxxxxx Xxxxxx		Name:	Xxxxx Xxxxxxx
Title:	Vice President		Title:	Chief Executive Officer
Acknowledged and Agreed:
MML SERIES INVESTMENT FUND
on behalf of MML Total Return Bond Fund
By:	/s/ Xxxxx Xxxxxxxxx
Name:	Xxxxx Xxxxxxxxx
Title:	CFO and Treasurer