Next time I have a relationship, I want it to be with someone who is also thinking about marriage.
Next time, I want to go out with someone who is on the same page as me regarding marriage.
「次付き合う人とはお互い結婚を前提にお付き合いしたい」＝ Next time I have a relationship, I want it to be with someone who is also thinking about marriage. / Next time, I want to go out with someone who is on the same page as me regarding marriage.
ボキャブラリー
go out with ～ / have a relationship （with ～）＝ 付き合う
on the same page as me ＝ 同じ事を考えている、共通認識
質問ありがとうございます。
こう言えますよ、
❶ I want to date someone who has marriage in mind.
(わたしは結婚を前提に置いてる人とお付き合いしたい)。
Next time I do date, I want to date someone who has marriage in mind.
(次誰かと付き合うときは結婚を前提に考えている人とお付き合いしたい)。
*marriage in mind は「結婚前提」です。
相手にこう聞けますよ、
A: Do you have marriage in mind? Or do you want to date just for fun?
(あなたは結婚を前提に考えてるの？それとも遊びで付き合いたいだけなの？)
B: Yes、I have marriage in mind。(はい、僕は結婚を前提に考えています)。
参考になれば嬉しいです！
イギリス 
アメリカ合衆国 
