Morane-Saulnier MS.755 Fleuret
The Morane-Saulnier MS.755 Fleuret was a prototype French two-seat jet trainer designed and built by Morane-Saulnier. It failed to gain any orders but was developed into the larger four-seat MS.760 Paris.
Source: Wikipedia — Morane-Saulnier MS.755 Fleuret (CC BY-SA 4.0)