cradle-snatcher someone who has a romantic or sexual relationship with a much younger partner (thefreedictionary.com) You could try forcing a neologism such as juvenophile, but any term with this general sense is likely to be derogatory and/or humorous.
Find us at the office
Kyker- Kublin street no. 42, 51864 Pretoria, South Africa
Give us a ring
+65 937 708 93
Mon - Fri, 10:00-20:00