Introduce both people
Give each partner a sentence in their own voice. For example, “I’m Alex, the one who always suggests live music. I’m Sam, and I’d probably pick a quiet café so we can hear each other.” A reader has two real details to ask about. Choose details you are both happy to make public.
Say what dating together means to you
Some couples like to meet other couples. Others would like to get to know someone who dates solo. Some meet separately. Say which applies to you and what is still open for discussion. If you practise ethical non-monogamy, spell out what your agreement means for the person reading it. They may use the same term differently.
Give the person who dates solo room to choose
If one of you usually answers messages, sign the first reply. Before suggesting a date, name everyone who plans to come and ask what the other person would enjoy. “Sam here. Alex and I would both love to meet you. Would coffee with the three of us feel comfortable?” gives them a specific invitation they can change or decline.